Current status of 3D printing in spine surgery

Abstract

Three-dimensional printing (3DP) is one of the latest tools in the armamentarium of the modern spine surgeon. The yearning to be more precise and reliable whilst operating on the spine has led to an interest in this technology which has claimed to achieve these goals. 3D printing has been used pre-operatively for surgical planning and for resident or patient education. It has also found its way to the operation theatre where it is used to fabricate customized surgical tools or patient-specific implants. Several authors have highlighted significant benefits when 3D printing is used for specific indications in spine surgery. Novel applications of this technology in spine surgery have also been described and though still in a nascent stage, these are important for this technology to sustain itself in the future. However, major limitations have also come to light with this technology in use. This article seeks to review the current status and applications of 3D printing in spinal surgery and its major drawbacks while briefly describing the essentials of the technology. It is imperative that the modern spine surgeon knows about this important innovation and when and how it can be applied to improve surgical outcomes.

Keywords: Additive manufacturing; Patient-specific implants; Rapid prototyping; Spine surgery; Three-dimensional printing.

Fig. 1

Import of images and creation of a digital 3D model. Individual vertebrae are subsequently separated.

Fig. 2

Marking the insertion points and trajectories of each individual vertebrae on the software.

Fig. 3

Creation of a reciprocal vertebral guide template for inserting screws.

Fig. 4

Individual 3D printed vertebrae and their corresponding guide templates.

Fig. 5

Jigs and 3D printed vertebrae assembled ex-vivo to check and validate the insertion point and trajectory.

Fig. 6

Drilling pedicle screw trajectory using a 3D printed jig during surgery.

Fig. 7

Flowchart denoting the process/methodology of creating a 3D printed drill-guide template to aid pedicle screw insertion using 3DP technology.